Currently, a roll-to-roll process or sheet-by-sheet process is used for manufacturing flexible electronic devices. The sheet-by-sheet process is able to utilize existing manufacturing equipment and processes for manufacturing display panels. In the sheet-by-sheet process, a rigid substrate is used as a carrier and a flexible substrate is formed on the rigid substrate. After forming the display device, the flexible substrate is separated from the rigid substrate. Conventional flexible substrate may include a polyimide (PI) film formed by coating and drying a PI solution on a glass substrate. Display devices may be formed on this coated PI film as the flexible substrate to provide a flexible display device. The coated PI film often has strong bonding with the glass substrate and thus is hard to be separated from the glass substrate.
Laser release technologies, such as laser lifting off (LLO) processes, may be used to de-bond the flexible substrate from the rigid substrate. When utilizing laser to illuminate the PI film, the PI film may be ablated and then separated from the glass substrate. During this course, laser controlling is significantly critical. When too-low laser energy is used, the PI film and the glass substrate cannot be completely separated from each other and the separation process may destroy the display device. When too-high laser energy is used, the PI film over the rigid substrate may be ablated and ashed. Transmittance of the PI film is decreased. This may create more undesirable issues particularly when transparent materials with high transmittance are used.
The disclosed methods for manufacturing the flexible display device may at least partially alleviate one or more problems set forth above and other problems.